(1)When the baby spanks the mother then the mother reacts by cuming in the babies eye.
(2)describing something rancid or nasty such as herpes
(3)a general fucktard
(4)describing a holy shit moment in your sucky life

(this is the original definition, and just the concept of a deen Bastard it can involve different people, such as son and father or boyfriend and girlfriend anyone can get a deen bastard)

Deen bastard can be used in many was, as a verb, adverb, noun, or even an adjective.

Ex.
I'm gonna deen bastard all over ur mom tonight.
Or
Man, that nasty. It taste like a deen bastard.
Or
dude it was so funny last night i got to deen bastard my girlfriend and i even video taped it, wanna watch.
Or even
I punish my baby when he does something bad by giving hime a nice big deen bastard and he learns his lesson.